Nvidia: ARM supercomputer to be more efficient than x86

SAN FRANCISCO--An ARM CPU is inherently more efficient than an x86 CPU and therefore best suited toward the high performance computing needs of the future, according to Nvidia Corp.

In a recent interview, Nvidia’s Sumit Gupta, director of Tesla marketing, said the only real advantage to x86 systems was that they could run operating systems like Microsoft Windows faster, but that when it came to needing maximum performance on minimum power, ARM was the future, and therefore a better option for supercomputing.

ARM architecture, explained Gupta, emerged out of the embedded space, where power limitations were prevalent and where less than a watt of power was considered a norm. All performance was therefore constrained from the conceptual phase of the chip’s design, forcing engineers to be especially creative about power efficiencies.

Intel and AMD’s x86 architecture, on the other hand, had been designed with PCs in mind, and came from a world in which machines were typically plugged in to wall sockets and faced no real power limitations.

“The number one consideration for x86 has always been to make operating systems like Windows run much faster and to be able to respond to unpredictable tasks, such as a mouse-click or a keyboard entry,” said Gupta, noting that the need for branch prediction and speculative execution was the reason x86 processors had such sizeable cache.

“It’s a terrific processor for everyday computing, not the right device as we go towards high performance computing,” he maintained.

Nvidia is already helping the Barcelona Supercomputing Center (BSC) to develop a hybrid supercomputer based on its Tegra ARM CPUs, accelerated by CUDA-supporting Tesla GPUs, with hopes of reaching exascale performance in a European project known as “Mont-Blanc”.

The hybrid will be the world's first ARM-based CPU/GPU supercomputing combination, and researchers at BSC have said they hope to achieve a short term goal of a two to five times improvement in energy efficiency compared with today's most efficient systems, with an ultimate goal of reaching exascale at 15 to 30 times less power.

Should the proof of concept work, Nvidia may well prove its point, but success seems a few years away at this point. In the meanwhile, Nvidia said it will continue working on a development board for the HPC community which the firm hopes will kickstart the software ecosystem around the ARM architecture for the supercomputers of the future.

I recently looked at some x86-64 code and was shocked at the number of push and pop instructions. Intel still only have 4 general purpose registers. All 16 registers on ARM are general purpose though you'd be silly to use r13-r16 (stack, link, program counter). That means more stuff in registers less pushing and popping. Just one example of how ARM is a more efficient design.

Reliability is a function of the implementation. So it would depend on the companies designing ARM cores and the RAS features they decide to put in.Intel Itanium e.g has a lot more reliability features compared to the x86 Xeons which again have more reliability features compared to the x86 corei5s used in the desktop parts.

Thanks to all of you for providing many important inputs on this topic. I think, I see majority is voting for ARM and I see very much valid justifications behind the opinion.
Other than performance, the next thing comes to my mind is reliability. What is your opinion about ARM vs. Intel?

To be a serious player, i believe ARM needs to deliver its 64-bit core first. Then we will see who will be winner. But it is no doubt there is better chance for ARM to move up to grab market share from Intel than Intel moves down to grab share from ARM. Because Intel is fighting this war by itself, ARM has entire ARMY around it. This Amry almost includes entire semiconductor companies except Intel and even larger software and tools partner. If Intel wins, the only company benefit is Intel. If ARM wins, there is long list of Companies you could name, starting from Apple, Google, Qualcomm, Samsung, etc. Even those tradition PC/Server companies such as HP & Dell could benefit from it to have alternative choice for their product. I could not imagine how Intel could win this war.
I think Intel should seriously consider build ARM product as well. if ARM is failed, good news. If ARM is successful, Intel could get its share as well.

sorry, I thought you meant core-counts-per-chip - that is, that HPC was pushing to more cores per node. sure, large clusters have lots of cores, since they have lots of nodes. it's not like this is optional: ambitious computing has necessitated for decades.

Well, let's see. The supercomputer used by NASA to discover Earth-like planets has 50,000 cores. I'm assuming it helps if unpredictable tasks can be managed more easily, in this sort of architecture. That core count sounds pretty extreme to me, although I suppose "extreme" is a relative term.
If extreme core counts are not involved then you'd still expect there to be a tradeoff between fewer, higher performing cores, as opposed to more, lower performing, but also lower power consuming cores.
But in general, I'l seeing a lot of arm waving going on here, me included. No one is offering specifics about the difference in the ARM vs x86 architecture. So I'm speculating only based on the popular press reports and common sense.